Control device



Dec. 23, 1941. w. s. LANDON CONTROL DEVICE Filed Feb. 16, 1939 2 Sheets-Shet l INVENTOR a my/d1. W M K W A}, ATTORNEY Dec. 23, 1941. w. s. LANDON 2,266,975

CONTROL DEVICE Filed Feb. 16, 1959 2 Sheets-Sheet 2 167 191 '19? -RL 190 204215 192N198 FIG-7 IINVENTOR aQGn/J. MKMW M ATTORNEY v Patented Dec. 1941 UNITED STATES PATENT OFFICE CONTROL DEVICE Walter S. Landon, Detroit, Mich., assignor to Detroit Lubricator Company, Detroit, Mich., a corporation of Michigan Application February 16, 1939, Serial No. 256,762

Claims.

My invention relates to new and useful improvements in heat operated power means and more particularly to such a means which is energized automatically or at the will of an operator. and is particularly adapted among other, uses for actuating a valve to control the supply of fuel to a burner.

An object of my invention is to provide a thermostatic operated means.

Another object is to provide a thermostatically operated means operable by an automatic means or at the will of an operator.

Another object is to provide means for maintaining a lag of operating time between enrgizatlon of the means and operation thereof.

Another object is to provide means for maintaining this lag of operation constant over a range of ambient temperature.

of the arrows and taken along the line 3-3 of Fig. 1;

Fig. 4 is a detail view in section looking in the direction of the arrows and taken along the line Another object is to provide means for regulating this lag of operation for use on any particular application.

Another object is to provide a liquid 'fuel flow controlling valve which will control the flow of liquid fuel in response to an automaticallyoperable means, and maintain constant the lag between operation of the operable means and flow through the valve means.

Another object is to provide a combined means for controlling the flow of fluid fuel and for controlling an igniting means to ignite the controlled I fuel.

l4 of Fig. 2;

Fig. 5 is a view of a portion of the apparatus of Fig. 1 showing a modification of my invention; Fig. 6 is a view of a portion of the apparatus of Fig. 1 showing a still further modification of my invention;

Fig. 7 is a diagrammatic view of a modified oil burning system showing in central vertical section a portion of a liquid fuel flow controlling device embodying a modified form of my invention; v

Fig. 8 is a detail view looking in the direction of the arrows and taken along the line 8-8 of Fig. 7;

Fig. 9 is a view of a portion of the apparatus of Fig. looking in the direction of the arrows and taken along the line 9-9 of Fig. 8, and

Fig. 10 is a detail view of a portion of the app'aratus of Fig. 7 looking in the direction of the arrows and taken along the line lU-ID of Fig. 7.

Referring to the drawings by characters of reference the numeral 1 designates generally a flow controlling device connected in an oil bumsystem including a heating means 2 having a fuel burner 3 which is supplied with liquid fuel from the flow controlling device I through a conduit l. A safety or control'switch 5 is carried by and is sensitive to a temperature condition of the heating means 2 so that upon a predetermined abnormal condition thereof the switch 5 is moved to open position. A room thermostat i comprises a temperature sensitive, bimetallic element 1 which is connected by a lead wire 8 to the switch- 5 and carries a contact member 9 which cooperates with a fixed contact member ill to control an electrical circuit. The thermostat 6 is located in a space which is heated by the heating means 2 andacts upon a predetermined low temclearly illustrated a preferred embodiment of my c invention, in which drawings- 4 Figure 1 is a view of a portion of an oil burnins system including a liquid fuel flow controlling device embodying my invention and shown in partial central vertical section; A I F g. 2 is a top plan view, with cover removed, of part of the apparatus of Fi 1;

Fig. 3 is a detail view looking in the direction perature to make circuit therethrough and acts upon a predetermined higher temperature to break the circuit therethrough. Lead wires H,

V I2, connected to the control device I in a manner to be hereinafter described, connect respectively the device I to contact member In and one side of the secondary coil of the transformer IS. The other side of the secondary coil of transformer I3 is connected by lead wire II' to the switch 5 to complete the electrical circuit. The primary of the transformer I3 is connected by lead wires l5,

I6 to a source of electrical energy supply.

The control device I comprises a chambered member 22 including an inlet orifice 23 controlled by a float operated. constant level inlet means 24 havinga float 25 operating an inlet controlling valve 26 which is operable to maintain a constant level of liquid within a chamber- 21, which level is designated by the line L-L. The chamber 21 is supplied with liquid through the orifice 23, a strainer chamber 28 and an inlet means 29. The inlet means 29 is supplied by an inlet conduit 39 leading from a source of supply (not shown). Secured by means of screws 3| to and closing the top or open side of the chambered member 22 there is a second cham-- bered member 32 having its open top or upper end closed by a cover 33 secured to the member 32 byscrews 34 (one of which is shown) which are screwthreaded into bosses 35. The bosses 35 project from and are part of the side walls 36, 31 of the member 32. The other side walls of the member 32 are ,designated by the numerals 38, 39 and cooperate 'with walls 36, 31 to form a chamber 49 open at each end, with one end openn downwardly into chamber 21 and the other end closed by the cover 33. A vertically extending, tubular outlet member 4| has an orifice or outlet port 42 therein, the member 4I projecting from the chamber 21 through the bottom wall of member 22 to the exterior thereof, as at 43, for threaded connection to an outlet conduit 4. A meteringneedle valve or pin 44 controls flow through the orifice 42 and has a stem portion 45 extending upward through the chamber 21 into the chamber 49 terminating in a portion of reduced diameter, as at 46. The portion 46 is guided within an aperture 41 located in a boss 48 which projects inwardly into the chamber 49 from and forms part of the side wall 31. The

- aperture 41, located in a vertical line above the outlet orifice 43, forms a guide for and is located in such a manner that the metering valve 44 is i freely held for reciprocal movement.

The reduced diameter portion 46 at its intersection with the normal diameter portion of the stem 45 forms a shoulder 49, and spaced therefrom on the reduced diameter portion 46 but below the boss 48 is an annular ring 59 of enlarged diameter, secured to the portion 46. The under and upper faces of the ring 59 form shoulders 52 for a use to be hereinafter described.

Screwthreaded into threaded apertures 53, 54 which are parallel to but spaced from aperture 41 and extending through the boss 48 are two stop members 55, 56 having abutment plates 51, 58 respectively which cooperate with the shoulders 5|, 52 respectively to limit-vertical movement of the valve 44 in its reciprocatory movement. A cup-shaped member 59 having a rectangular flange portion 69 and overlying an aperture 6| in the wall 38 of chamber 49 is secured to the wall 38 by means of screws 62 inserted through apertures in the corner portions of the flange 69. A terminal member 63, secured to the bottom portion of the member 59 on the side away from the chamber 49 by means of screws 64, has an aperture 65 extending therethrough and aligned with an aperture 66 through the bottom of the member 59.

One end of a supporting pin 61 is secured within the aperture 66, as by peening, and the other end is secured within a cup-shaped member 68. The lip of the cup-shaped member 68 faces the bottom of member 59 and is enlarged to form shown, toward and into the chamber 49 where it is secured andsealed to an annular end plate 1 I. An attaching screw 12 is. secured and sealed within a central aperture 13 through the plate 1|. Screwthreaded to the attaching screw 12 is one end of a horizontal, movable connecting member 14 having its opposite end screwthreaded to an attaching screw 15. The screw 15 is secured in fluid-tight relation within an aperture through the bottom wall of a-cup-shaped member 16. The member 16 has an annular ring 11 extending circumferentially from its lip edge portion which projects toward the bellows 19. A bellows 18 is sealed at one end to the ring 11 and sealed at the other end, as at 19, to the peripheral edge of an annular plate 89 secured to a thimble member 8|. The thimble member 6| is carried within an aperture 82 extending through an inwardly projecting boss 83 of the wall 39, and a shoulder 84 on the member 8| abuts the inner end wall of the boss 83. A threaded portion 85 of the member 8| projects loosely through a reduced portion 86 of the aperture 82 and extends externally beyond the wall 39. The extended portion 85 has a holding nut 81 screwthreaded thereon which serves to hold the thimble member 8| securely to the shoulder 84 by engagement of the nut '81 with the wall 39. The attaching screw 15 has a central aperture 88 therethrough which communicates with the chamber formed within the bellows 18 and, after charging of the bellows, is sealed externally thereof in a convenient manner, as at 89. A screwdriver slot 99 serves as a means for rotating the screw 15 thereby'to exert more or less of the inherent resiliency of the bellows 18 tending to oppose movement of the bellows 19.

A pair of inwardly projecting bosses 9|, 92 having threaded apertures 93, 94 therethrough project into the chamber 49 from and are inte-' gral with the Walls 36, 31. Threaded into the apertures 93, 94 are pin fulcrum members 95,

96 upon which are fulcrumed a lever member 91 connecting the valve 44 --to the power element bellows 10. The member 91 is dished and has two arms 98, 99 which in this instance are of unequal lengths and have aligned apertures therethrough to receive the fulcrum members 95, 96. A pair of ears I99 are displaced from the centerline of the fulcrum members 95, 96 and extend into a central aperture I9I of the dished,

portion of member 91 so that movement of the ears I99 by the member 14 will cause the member 91 to rotate about the fulcrum members 95, 96. The ears I99 are received in a peripheral cut I92 in the connecting-member 14, which cut I92 is of suflicient width to permit some twisting movement of the ears I99 so that movement caused by the rotation of the lever member 91 about the pins 95, 96 will not cause the ears I 99 to bind. The arm 99 extends beyond the fulcrum member 96 and terminates in a circular engaging portion I93 fitting between the shoulders 49, 5| and by engagement with the shoulders is operable to reciprocate the valve 44 and thereby to control the flow through orifice 42.

A ring I94 is press-fitted into the open end of an aperture I95 within the thimble member 8|, and an extension on the attaching screw 15 carries. an abutting portion I96, which portion I96 cooperates with the ring I94 to' limit expension of the bellows 18. The plate 1I, bellows an outwardly facing annular flange 69. One end- 19 and cup-shaped member 68, cooperate to form a sealed, pressure responsive chambered member I91 having a chamber I 91.

The cup-shaped therein is similar to that of Fig. 5.-

member 16, bellows '18 and annular plate 80 cooperate to form a second sealed, pressure'responsive chambered member I08 having a chamber I08. These chambers I01, I 08 are evacuated and the chamber I 01 is charged with a volatile, temperature responsive fluid such as ethyl ether. Preferably the chamber I08 formed within the bellows 18 is charged with a fluid having a higher vapor pressure at a given temperature than that of the fluid in chamber I01", and which fluid may be ethyl chloride. The fluid charge in both chambers may be of such quantity that at all operating temperatures a small quantity thereof is in the liquid state, but at no time should the quantity of liquid be sufllcient to exert a hydraulic force within the chambers. The bellows 10, 18 may be of equal cross-sectional area bered member 22. Electrical energy from a source of supply is introduced through main lead wires I5I and I52 connected to terminal posts I53, I54 respectively of a terminal block I55. An ignition transformer I56 has one end of its primary coil connected by a lead wire I51 to the main lead wire I5I through terminal post I53, and the other end of the primary coil connected by means of so that the difierence in the forces exerted by the contained fluids is dependent upon the pressure within the chambered members I01, I08.

Sealed by an electrical insulating cement I08,

within the cup-shaped member 68 and surrounding the supporting pin 61, there is a cylindrical shaped, electrical resistance heating unit IIO having lead wires III leading to external termi- 1 119.15 H2, H3 on the terminal member 63 and insulated thereby from each otherand from the member 59. The terminals H2, H3 receive the lead wires II and I2 respectively so that the heater is under the control of the thermostat 6, and upon closing of the thermostat 6 an electrical circuit is made from the transformer I3, lead wire I4, switch 5, lead wire 8, bimetallic element 1, contact members 9, I0, lead wire II, heating unit II and lead wire I2 back to the 7 transformer I3. Should the heating means 2 be I01 will expand to urge,the valve 44 toward open position. The expansion of member I01 will collapse the member I08 an equal amount.

In Fig. where like numerals designate like parts, the chambered member I08 is replaced by a bimetallic strip I secured to the wall 39 by arivet I 2I. An adjustment member I22 screwthreaded 'to the connecting member 14 is slidably received in the aperture 82 within boss 56 and serves as an adjustment means to regulate the relative efiects of the bimetallic strip I20 and the chambered member I01. A portion I23 of member I22 is received by the aperture portion 86 through the wall 39 and extends through the wall to abut and engage the bimetallic strip I 20 which is sensitive to ambient temperature and operable to oppose movement of the member 14 due to increased temperature of the chambered member I01.

In Fig. 6 the bimetallic strip I is located within the chamber 40 and is received within a groove I26 within a member I21 instead of being located as is the bimetallic strip I20 of Fig. 5. In other respects however the modification shown In Fig. 7 I have shown adifierent application of my invention. A chambered member 150 is similar to and adapted to be substituted for the a lead wire I58 to a terminal post I59 carried by the terminal block I 55. The secondary coil of the ignition transformer I56 is connected to an igniter for igniting the fuel oil at the burner, and diagrammatically shown in the drawings as a resistance I00. A lead wire I6I is connected to main line I5I and leads to the primary coil I62 of a transformer I63, the other side of the primary coil I62 being connected by means of a lead wire I64 to the main lead wire I52. The secondary coil I65 of the transformer I63 has one end thereof connected by means of a lead wire I66 to a terminal I 61 secured to a second terminal block I68. The other end of the secondary coil I65 is connected by means of a lead wire I69 to a contact post I10 also carried by the terminal block I68.

7 "I is connected to the terminal post I61,and

chambered member 32 of Fig. l on the cham- 7 the other end is connected to the stationary contact I12 of a room thermostat, diagrammatically shown and designated I13. A movable contact member I14 is carried by a bimetallic temperature sensitive element I15 of the room thermostat I13 and is electrically connected through the element I15 and a lead wire I16 to a terminal post I11 also secured to the-terminal block I68. A lead wire I18 connects the terminal post I11 to one contact of a switch, diagrammatically shown at I19, which switch is preferably sensitive to an output of the heating means so that upon an abnormal condition thereof the switch I18 is moved to open position. The other contact of the temperature sensitive switch I19 is connected by means of lead wire I to a terminal post I 8I secured to the terminal block I60.

The chambered member I50 has end walls I82, I83 and a cover member I8'4. Secured within an aperture I85 in the end wall I82 is one end of a bolt-like member I86 having at its other end, which other end is located within the chambered member I50, a plate-like head portion I81. A pair of nuts I88, I89 are threaded onto the bolt member I86 so that the nut I 88 is within the casing and the nut I89 is without the casing. The member I86 is rigidly secured to the end wall I82 by the nuts I88, I89 which clamp the member I86 tightly to the wall I82. The nuts I88, I88 are also used as an adjustment means to be hereinafter described. Sealed to the plate-like portion I81 is one end of a bellows member I90. The other end of the bellows member I90 extends toward the end wall I83 and is sealed in fluidtight relation to a disc or head member I8I. A heat conducting thrust member I92 has one end I83 extending centrally through the disc member I 9I within the bellows member I90 and sealed in fluid-tight relation to the member I9I by means, such as solder I84. The other end I950! the thrust member I92 is secured, by means such as solder I96, centrally within a disc member I81.

Secured in fluid-tight relation to the disc member I91 is one end of a bellows member I88. The

other end of the bellows member I88 extends.

toward the end wall I83 and is secured in fluidtight relation to an outtumed flange I88 of a cup member 200. The bottom end wall 20I of the cup One end oi. a lead wire effect of heater 206.

manner by an abutment member 202 held, as by a clamping nut 203, to the end wall I83. The bellows member I90 cooperates with the members I81, I9I to form a temperature sensitive, expansible-contractible, chambered member 205 having a chamber 200*, while the bellows member I98 cooperates with the members I9'I, 200 to form a second expansible-contractible, temperature sensitive chambered member 205 having a chamber 205. The end portions of the thrust member I92 engage the end wall 20I and the head portion I81 of the bolt-like member I80 to limit the reciprocal movement of the thrust member I92 under influence of the pressure responsive chambered members 200, 205.

Surrounding the cup member 200 and intermediate the flange portion I99 and the end wall- 20I is a suitable electric heater 200 having one end thereof connected by means of a lead wire 20? to the terminal post I8I. The other lead wire 200 of the heater coil 205 is connected: through an electric switch means 200, which may be a mercury tube type switch, the operation of which will be described in detail hereinafter, to contact post I'l0. The chambers 200 205 contain volatile, temperature sensitive fluids, in accordance with the teachings of Fig. 1. The fluid within reciprocal movement of the thrust member I92 will rock the switch means 2I0 into circuit making and circuit breaking positions. The switch means 2l0 has one lead wire 2I0 connected to the chamber 200 will preferably have a higher fluid I that within the chambered member 205 and the thrust member I92 will be urged in a direction v toward and against the end wall I03 similarly to that described in connection with Fig. 1. The temperature sensitive fluids used in chambers 200 205 in the construction of Fig. 7, are furthermore so proportioned relative to each other and to the heat output of the heater 205 andthe thermal conductivity of the member I92, that shortly after energization of the heater 205 the fluid pressure in the chamber 205 will exceed that within the chamber 200 due to the heating This will cause the thrust member I92 to be urged in a direction toward the end wall I82. Upon continued heating of the heater 206 the heater will assume .a predetermined maximum temperature and' heat will be conducted from the heater 206 through the volatile fluid in the chamber 205 and the heat conducting thrust member I92 to the volatile fluid contained within the chamber 200, and after a predetermined time the temperature of the fluid within the chamber 200 will have risen sumciently so that the pressure therein will exceed the maintained pressure within the chamber 205 and the thrust member I92 will be urged toward the end wall I83. It is seen that I have a heat opcontact post I59 and the other lead wire 2I9 connected to the terminal post I50. The switch means 200 is carried by a U-shaped member 22I in a similar manner as the switch means 2I0 is carried by the member 2I I. A bell crank member 222 has one arm 223 extending upward through an aperture 220 in the cover I00 of the chambered member I50. The other arm 225 of the bell crank member 222 has a pair of downwardly turned ears 225. A rod-like pivot member 22? is carried by a side wall 220 of the chambered member I50 and extends through a pair of aligned apertures in the ears 225 so that the bell crank member 222 may be rotated about the member 22?. An end portion 229 of the bell crank arm 223 extends externally of the cover member I80 and serves as a manual means for rotating the bell crank member 222 to cause the switch means 209 to make and break the circuit through the lead wire 207.

The U-shaped member 22I is secured to the upwardly facing surface of the arm 225. Secured to the under surface of the arm 225 is one arm of an s shaped member 230, the purpose of which will be described hereinafter. Secured to the end wall I83 of the casing I50 is one end 23I of an L-shaped member 232 having a horizontally extending portion 233 projecting toward the end erated ,device which upon energization moves in one direction and after a predetermined time moyes in the reverse direction.

A switch means 2I0 which may be a mercury tube type switch is carried by a. U-shaped member 2I I secured to a pivoted member 2I2 pivotally secured to a rod-like pivot 2I3 carried by a side The portion of the thrust rod I92 intermediate the plate members I9I, IQ'I is suitably threaded, and threaded thereon is a pair of adjustment nuts 2 I 5, 2I6. The pivoted member 2I2 has a projecting portion 2I'I which projects downward and is received intermediate the members 2 I 5, 2 I 5 so that 'gages the upper abutment plate 58 of the stop member 55 to open the outlet port 02 to flow of liquid fuel. Continued heating of the heater 200 r acts through the bimetallic member 235 to maintain the valve 00 in open position as long as the heater 205 remainsenergized. The lower arm 231 of the s-shaped member 230 cooperates upon rotation of the bell crank member 222 with the portion 236 of the thermostatic member 235 to force the portion 236 downward, thereby to close the valve member 00 and open the circuit through theswitch means 209, and which is described more fully hereinafter.

The operation of my flow controlling device or heat motor, as shown in Fig. 1, is as follows: When the thermostat 5 is not in circuit closed position (calling for heat), the heater unit IIO will be deenergized and both chambered members I07, I00 will tend to assume ambient temperature, which for purposes of exposition we shall assume to be 30 F. Upon reaching am bient temperature the fluid pressure of the ethyl ether within member I01 will be approximately 3.3 pounds per square inch absolute, while the fluid pressure of the ethyl chloride in member 7 I08 will be approximately 8.5 pounds per square ing unit IIO will be energized and the pressure of the fluid within chamber I01 will increase due to the increase in temperature thereof by the unit IIO. It may be seen from a table of the pressure-temperature relationships for ethyl chloride and ethyl ether that at a temperature of approximately 69 F. the pressure of the ethyl ether will be 8.5 pounds per square inch, or that with the temperature of the ethyl chloride at ambient, or 30 F., and the temperature of the ethyl ether at 69 F., the opposing forces exerted by th members I 01, I08 will be equal so that upon any further increase in temperature of the ethyl ether within chamber II the pressure in chamber I0'I will tend to expand the bellows I0 to move the valve member 44 toward open position. The bellows I8 of chambered member I08 will collapse somewhat, but as the pressure exerted by the ethyl chloride within chamber I08 .is substantially vapor pressure corresponding to the liquid temperature, any collapsing movement will not cause a substantial increase in pressure but will merely cause some of the vapor therein to condense into a liquid state. This is true in instances where the change in volume per unit of time is a small percentage of the whole volume, and the heat given up by the condensing vapor is small in respect to the heat absorbing matter in intimate relationship. therewith. It has now been shown that to move the valve to open position it is necessary to raise the temperature of the ethyl ether to slightly more than 39 F. above an ambient temperature of F., and that with both liquids at the ambient temperature of 30 F. the connecting member I4 is urged in a closed direction with a force of 5.2 pounds per effective square inch of the bellows cross-sectional area.

Suppose that the ambient temperature of 80 F. existed, then the pressure of ethyl ether would be 10.8 pounds per square inch absolute and the ethyl chloride would be at 24.2 pounds per square inch absolute. The connecting member I4 will be urged toward valve closing position with a force of 13.4 pounds, assuming as before one square inch of effective cross-sectional area of the bellows. To equalize the pressure of the two bellows chambers it is necessary to raise the temperature of the ethyl ether to l20.5 F., or an increase of 405 F. above the ambient temperature of 80 F., at which time a further increase of temperature of the ethylether will cause a valve opening force as described in connection with the 30 F. ambient operation. It will be noticed that the rise in temperature of the ethyl ether necessary to overcome the force of the ethyl chloride has remained substantially constant even though the difl'erential force at the two ambient temperatures was decidedly different. Itmay further be seen that as the am-' bient temperature increases, the fluid pressure within the bellows chamber corresponding to ambient temperature increases. were pr vided to exert an increasing opposing as the pressure chamber containing ethyl chloride, the increase'in fluid pressure or tempera ture rise above ambient needed to open the valve would be decreased due to the increased pressure at ambient temperature.

If no means screw driver in the slot 90. The rotation is force wi h increasing ambient temperature, such The heater element supplies heat to the liquid containing chamber the ambient temperature, which is undesirable in many applications. With my apparatus however the rise in temperature above ambient is maintained substantially constant, and as my heater is maintainedat a constant output and the mass to surface ratio balance is maintained constant, the time elapsing between energization of the heater and operation of the heat motor is constant.

I have designed my heater to run continuously as long as it is desired for the heat motor to operate, and furthermore it is designed to maintain a predetermined constant differential between ambient temperature and the fluid temperature within the actuated bellows. In my particular application I have found that 140 F. is satisfactory for th temperature rise caused by continuous operation. At 30 F. ambient temperature this would mean a maximum fluid temperature of 170 F. while at an ambient temperature of F. it would mean a maximum fluid temperature of 220 F. As the maximum temperature rise caused by continuous operation of the heater is constant, and the temperature rise above ambient tooperate the valve is substantially constant, the difference between the two, or the temperature drop required to move the valve from open to closed position, is constant.

The relative times between openingof the valve upon energization of the heat motor and closing of the valveupon deenergization of the heat motor may be adjusted or varied at will by loosening the nut 81 and rotating the thimble member 8| by a suitable instrument, such as a transferred through the bellows I8 and cupshaped member I6 to the screw I5 which moves longitudinally in the member- H to vary the innate resiliency of the bellows I8. If greater adjustment-is desired, a spring or springs could be interposed in a convenient manner to augment the innate resiliency of the bellows.

In the apparatus shown, I apply an electrical voltage to the terminals I I2, II3 of the electrical heating unit H0 by means of the transformer I3 and the thermostat 6, as described hereinbefore, and heat starts to flow to the fluid in the chamber I01. After a predetermined time the fluid pressure in the chamber I0'I will equal and then become greater than that in the chamber I 08' and will expand the chambered member I01 to move the connecting member I4. The ears I00 of lever member 91 will be engaged by the walls of the slot I02 and the lever member 9! will be rotated thereby about the fulcrum members 95, 96. The rotation of the lever member 91 will raise the valve 44 until the shoulder 52 engages and is stopped by the plate 58. Further increase in fluid pressure within th chamber I01 will cause a tighter engagement between the shoulder 52 and plate 50, but substantially no further movement either of the. connecting member 14 or lever member 01.

After a given elapsed time, the fluid in chamber i01 will have attained the maximum temperature, or 140 F., above ambient temperature. Upon deenergization of the heater IIO the fluid starts to cool to ambient temperature. The tem-' perature of the fluid in chamber I01 decreases and the pressure likewise decreases until at the substantially constant temperature rise of 40 F. above ambient temperature, or F. below the maximum temperature rise, the valve begins to 0 .6. As the mass to surface ratio and the rabeing without and the strip I25 being within the chamber 00. The strips I20, I25 act with increasing force to urge the valve in a closing direction with increasing temperature. These bimetallic strips I20, I25 if correctly proportioned and shaped will perform as effectively as the chamber I08. Adjustment in this'modiflcation is accomplished by means of the adjustment member I22 screwthreaded to the member 10 (not shown in Fig. 6).

The operation of the device as illustrated in Fig. '7 is similar to that of Fig. 1 but, becaus of the-thermal conductivity of the thrust member I92, diifers therefrom and operates as follows: Electrical energysupplied from a suitable source through lead wires I5I, I52 energizes the transformer I63. The output of the transformer is controlled by the' thermostat I13 located in the space which is heated by the burner. Upon decreas in temperature of thebpace heated by the burner, the bimetallic element I15 moves the contact member I14 into engagement with the stationary contact member I 12 thereby completing a circuit from the secondary coil I65 of the transformer I63, lead wires I66, I1I, thermostat I13, lead wires I16, I18, switch I19, lead wires I80, 201, heater 206, lead wire 208, switch means 200, and lead wire I69 to the other sid of the secondary coil I65. Under normal operation of the system the switch means I19, 209 will remain in circuit closed position, the switch means I19 acting to desired temperature being reached within the space, the bimetallic element I15 moves the movable contact member I10 away from the stationary contact member I12 to open the electrical circuit, hereinbefore described, controlling the energization of the heater 206. Upon deenergization of the heater 206 the temperatures of the chambered members 200, 205 and the bimetallic element 236 begin to decrease toward ambient temperature. This decrease causes the bimetallic element'236 to move the valve member 00 toward closed position, thereby stopping flow of fuel to the burner. The chambered members 200, 205 whil cooling to ambient temperatures will maintain the thrust member I92 in its position toward the end wall I83 as the fluid pressure in the chamber 206 will always exceed the fluid pressure in the chamber 205.

If for some reason the fuel fails to ignite in the burner 3, it will be necessary to manually reset the control means because the thermostat I13, under such a condition, will continue to call for heat and the switch means 2 I0 and fuel valve 00 will be in open position and remain in that position until either the manual reset mechanism is moved to open switch 209 or the thermostat I13 is manually moved to Open position. Rotation of the end portion 229 of the bell crank member 222 in acounterclockwise direction (as shown in Fig. 7) forces the lower portion of the S-shaped member 230 over the horizontal portion 236 of the bimetallic member 235 so that the metering valve 04 is moved against its lowermost stop member to cut-ofi flow of fuel to the burner 3. This movement will place the bimetal under tension because of its tendency when open the circuit upon a predetermined abnormal temperature condition of the heating means to prevent injury thereto, .and the switch means 209 being manually opened by means of the bell crank member 222 upon an abnormal condition such as failure of the burner to ignite. Upon closing of the circuit by the room thermostat I13, the heater 206 heats the fluid in the chamber' 205 increasing the fluid pressure of the volatile fluid contained therein to force the thrust member I 92 toward the end wall I82. Movement of the thrust rod I92 toward the end wall I 82 acts through the member 2I2 to rotate the switch means 2I0 into switch closed position, thereby closing 'a circuit leading from the main lead wire I52, lead wire 2I9, through switch means 2I0, lead wires 2I8, I58, the primarycoil of the transformer I56, and lead wire I51 back to the main lead wire I5I. As the secondary of the transformer I56 is continually connected to the igniter I60, closing of the switch means 210 en-,

ergizes the igniter. After a predetermined time heated by the heater 206 to move in a valve opening direction. Movement of the member 222 will also rock the switch means 209 to open the circuit through the room thermostat I13 and heater 206.

'After the heater 206 has cooled substantially to interval the temperature of the fluid within the chambered member 204 is raised sufliciently so that the fluid pressure within th chambered member 204 becomes greater than the fluid pressure in the chamber 205?, and the thrust member I92 is moved toward the end wall I 83 to rotate switch means 2 I0 into open circuit position thereby deenergizing the igniter I60. During the time that the heater 206 has been supplying heat to the members 204, 205 it is also supplying heat to the bimetallic member 235 so that the horizontal ambient temperature, the bimetallic member 235 will have assumed its cold or valve closed position and the S-shaped member 230 will be free from and slide from the horizontal portion 236 so that the vbell crank member 222 can rotate clockwise to place the switch means 209 in circuit closed position so that if the thermostat is in, or again assumes, circuit closed position, the normal cycle -of operation will result. It will be noted that the switch 209 will automatically return to operating position upon cooling of the heater 206, while if the thermostat I13 is used it must be manually reset for subsequent operation. It is to be understood that the manual operation which has just been described is an emergency measure and therefore previous to the resetting operation, care should be exercised to search for and correct the trouble which rendered such operation necessary. One trouble which might cause such operation is the burning-out of the igniter I so that upon the thermostat I 13 calling for heat and the switch means 2I0 being moved to closed position, the oil flowing to the burner 3 will not be ignited and consequently portion 236 thereof will have moved the valve member 44 to valve open position. Under normal operation the burner is now energized and is supplying heat to the heated space. Upon the the heating means 2 fails to supply heat to the heated space.

The apparatus shown in Fig. 7 may be regulated or adjusted to regulate the time interval for .the various operations. The length of time required for the heater 206 to cause the switch 2I0 to be moved to on position and again to "ofi position is regulated by means of the nuts I88, I89 which position the bolt-like member I86 rigidly with respect to the casing end wall I 82. Movement of the. bolt-like member I86 toward the end wall I83 will, by utilizing the inherent resiliency oi the bellows members I90, I98, tend to increase the length of time elapsing between the energization of the heater 286 and the movement of the thrust member I92 toward the end wall I82, and will decrease the time required for the reverse movement toward the end wall I88, while the reverse adjustment of the bolt-like member I86 will have the opp site eifect. Further adjustment may be had .by using spring members (not shown) to add or subtract from the normal resiliency of the bellows members I98, I98, so that a greater change of resiliency or a different ratio of resiliency change might be accomplished by the positioning of the bolt-like member I 86. Adjustment of the members 2 I 5, 2 I 6 will vary the relative proportions of the time the switch 2"! is onv with respect to the time that the switch is ofl. To be more specific, if the member 2I5 is moved toward the head portion I81, the length of time between energization of the heater 288 and the movement of the switch means 2III to on position will be increased and the length of time required for the heater to move the switch means 2I8 to closed position remains unchanged, while movement of the member 2I6 toward the disc member I91 increases the length or time necessary for the heater 288 to move the switch means 2I8 to closed position and, with no movement of the member 2 I5, maintain constant the time the switch 2l8 is moved by the heater 286 to open position.

It will thus be seen that by means of my invenheating means operative to increase the fluid pressure in said one chamber, said chambers being operatively connected in opposition and to,

operable to expand said chamber in response to temperature increases, one end wall of said chamber being secured in fixed spaced relation to said supporting member, a movable connecting member having one end portion securely fastened to the other end wall of said chamber, an

electrical resistance heating means having a constant output in heat exchange relation with said fluid in said chamber and operable to cause said fluid to expand said chamber, a second bellows member hermetically sealed to form a second expansible-collapsible chamber, a temperature responsive fluid within said second chamber and having a pressure-temperature curve similar to that of said first-named fluid buthaving tion I have a heat motor which is shown on a fluid flow device and which is automatically operable to produce a laglbetween theoperation of the energizing means and operation of the L valve. Further, I have an apparatus which may be adjusted for any given desired ratio of operating times between opening and closing by changing the inherent resiliency of the bellows, or by changing the voltage applied to the heater coil the opening and closing may be maintained at any given, absolute lag. An apparatus 01'- this type may be used at various ambient temperatures and yet maintain a substantially constant lag in operation. I have also invented a timing means which when energized will cause a means .to be actuated, and upon continued energization of the first-named means the actuated means will be moved to the original or unactuated position according to a predetermined timing schedule. I have further disclosed means for varying the time schedule so that the time periods required to actuate the actuated means and also to move the actuated means to its unactuated position may be adjusted for different conditions of operation.

What I claim and desire to secure by Letters Patent of the United States is:

1, In a controlling device, a casing, a plurality of bellows members, each of said members comprising an hermetically sealed temperature responsive expansible-collapsible chamber, a conupon a predetermined substantially constant increase in temperature of said first-named fluid relative to the temperature of said second fluid,

a higher pressure for each corresponding temperature, one end wall of said second chamber being secured to the opposite end of said movable member, the other end wall of said second chamber being secured to said supporting member, said second chamber being responsive to ambient temperature and operable to oppose movement of said first chamber, said movable member being operatively connected to said controlling means, and stop means operable to limit movement which can be imparted to said controlling means by said movable member.

- 3. A controlling device comprising a casing, a

controlling means within said casing, a bellows member hermetically sealed to form an expansible-collapsible chamber, a temperature responsive fluid in said chamber and operable to expand said chamber in response to temperature changes and having a pressure-temperature curve, one end wall of said chamber being secured in fixed spaced relation to said casing, a movable connecting member having one end securely fastened to the,other end wall of said chamber, a heating means having-a constant output in heat exchange relation with said fluid in said chamber and operable to heat said fluid thereby to cause said fluid to expand said chamber in accordance with said curve, a second bellows member hermetically sealed to form a second expansible-collapsible chamber, a temperature responsive fluid within said second chamber and having a second pressure-temperature curve, said second curve being substantially similar to said first-named curve but displaced therefrom, one end wall of said second chamber being secured to the opposite end of said movable member, the other end wall of said second chamber being secured to said casing, said second chamber being responsive to air temperature within said casing and operable to oppose movement of said first chamber, and means operatively connecting said movable member with said controlling means so that movement of said movable member will move said controlling means.

4. In a control device, a pair of temperature responsive elements acting in opposition against each other, said elements being so constructed and arranged that one of said elements exerts a greater force than the other of said elements when both of said elements are at substantially equal temperatures, a control device movable by .said elements, means limiting the movement of the other of said elements by said one element so that said control device will have a predetermined position when said elements are at substantially equal temperatures, means to heats said other element independently of said one element so that said other element will overcome l0 ment will'overcome said other element and move said control device to said device predetermined position;

5. In a control device, a pair of temperature responsive elements acting in opposition against each other, one of said elements having a first 2 predetermined force-temperature curve, the other of said elements having a second forcetemperature curve, said curves being similar and spaced from each other, said first curve being spaced above said second curve so that 2 said one element exerts a greater force than said other element when both of said elements are at substantially the same temperature, a control device movable by said elements, means limmember carried by one of said opposed members and having a first movable wall facing the other of said opposed members, a second bellows member carried by said other opposed member and having a second movable. wall facing said first movable wall and spaced therefrom, a thrust rod rigidly connecting said movable walls and having a first extending portion extending through said first movable wall and into said first bellows member and having a second extending portion extending through said second movable wall and into said second bellows member, a first tempera- "ture sensitive fluid within said first bellows member and in heat exchange relationship with said first extending portion, a second temperature sensitive fluid within said second bellows member and in heat exchange relationship with said second extending portion, said fluids being so interrelated that when both of said fluids are at the same temperature said first fluid exerts a less expansive force on said first bellows member than said second fluid exerts on said second bellows member, means for heating said first fluid thereby to iting the movement of the other of said elements by said one element so that said control device will have a predetermined position when said elements are at substantially equal temperatures, means to heat said other element independently of said one element so that said other element will overcome said one element and move said control device, and means to transmit the heat of said heating means from said other element to said one element so that the force exerted by said one element will overcome said other element and move said control device to said device predetermined position.

6. In a device of the character described, a supporting means, means mounted for reciprocal movement, a pair of expansible-contractible' temperature sensitive chambers having movable walls, one of said chambers having its movable wall connected to and opposing movement of the movable wall of the other of said chambers from said one position of said walls to a second posi-' 59 tion of said walls, said reciprocal means being I' moved from one position to a second position upfluid pressure thereby to cause said other cham- 6 ber to" expand and to move said reciprocal means to said other position, and means operable upon a continued heating of said other chamber to raise the temperature of said first-named fluid thereby cause said first fiuid to exert an increased force on said first movable wall, said increased force causing said first bellows member to expand and said second bellows member to contract, said first extending portion acting to receive heat from said first fluid upon continued heating of said first fluid by said heating means, said rod acting to transmit heat to' said second extending portion to heat said second fluid, said second fluid upon heating by said rod acting to increase its force exerted on said second. movable wall so that said second bellows member will expand and cause said first bellows member to contract, and means reciprocated by said rod member upon movement by said bellows members.

8. In an automatically operated device, a pair of opposed supporting members, a first bellows member carried by one of said opposed members and having a first movable wall facing the'other of said opposed members, a second bellows member carried by said other opposed member and having a second movable wall facing said first movable wall and spaced therefrom, a thrust rod rigidly connecting said movable walls and having a first extending portion extending through said first movable wall and into said first bellows member and having a second extending portion extending through said second movable wall and into said second bellows member, a first temperature sensitive fluid within said first bellows member and in heat exchange relationship with said first extending portion, a second temperature sensitive fluid within said second bellows member and in heat exchange relationship with said second extending portion, said fluids being so interrelatedthat when both of said fluids are at the same temperature said first fluid exerts a less expansive force on said first bellows member than said second fluid exerts on said second bellows member, means for heating said first fluid thereby to cause said first fluid to exert an increased force on said first movable wall, said increased force causing said first bellows member to increase said first-named fluid pressure above of opposed supporting members, a first bellows to expand*and said second bellows member to contract, said first extending portion acting to receive heat from'said first fluid upon continued heating'of said first fluid by. said heating means, said rod acting to transmit heat to said second extending portion to heat said second fluid, said second fluid upon heating by said rod acting to increase its force exerted on said second movable wall so that said second bellows member will ex pand and cause said first bellows member to contract, means reciprocated by said rod member upon movement by said bellows members, means engageable by said first extending portion upon movement of said rod due to expansion of said second bellows member, and means engageable by said second extending portion upon movement oi said rod due to expansion of said first bellows member, said first-named and said secondnamed engageable means acting to absorb any excess force exerted by either of said bellows members.

9. A control device comprising a controlling means, a temperature responsive element operable to move said controlling means, a second responsive element inherently exerting a greater force than said first-named responsive element for all equal temperatures acting on said elements, said second temperature responsive element holding said controlling means against movement by said first-named responsive element, and means to heat said first-named responsive element to a temperature to overcome the greater force of said second responsive element and move said controlling means.

10; A control device comprising a controlling means, a temperature responsive element operable to move said controlling means, a second esponsive element inherently exerting a greater orce than said first-named responsive element for all equal temperatures acting on said elements, said second temperature responsive element holding' said controlling means against movement by said first-named responsive element, means to heat said first-named responsive element to a temperature to overcome the greater force of said second responsive element and move said controlling means, and means operable during the heating of said first-named responsive element to transfer heat from said heating means to said second responsive element to return said controlling means against the force of said firstnamed responsive element.

WALTER S. LANDON. 

